32-Bit means there's 256 red levels, 256 green level, 256 blue levels, and 256 transparency levels. Usually, the number of colours is determined by a power of two. For example, if the display was 20-bit, the number of colours would equal to 2 ^ 20 or 1 048 576.
About these benchmark programs, where can I get them? And also, would someone be able to check my XFree86 configuration file I attached with this post to see if there is anything wrong with it. I'm running a GeForce4 MX 420 (64 MB), but Mandrake-Linux 9.0 reads it as a GeForce 2 DDR (generic). The reason why I would like to have this checked is since I installed the kernel and GL drivers via the tarball method and modified this file (originally XF86Config-4, just renamed for your understanding), KDE will no longer work and none of the KDE-based applications will work neither. This would be the reason why the X server login window didn't show at start-up because it's KDE-based. Any help would be appreciated.